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HomeMy WebLinkAboutAgenda 06-27-06 Web AGENDA #2613 SPECIAL CITY COUNCIL MEETING CITY OF UNIVERSITY PARK COUNCIL CHAMBERS TUESDAY, JUNE 27, 2006, 5:00 P.M. 4:00-5:00 P.M. WORK SESSION FOR AGENDA REVIEW I.MAIN AGENDA FINAL REPORT: 138kV Transmission Line II. ITEMS FROM THE FLOOR Anyone wishing to address an item not on the Agenda or having questions about items on the Consent Agenda should do so at this time. Questions and comments regarding Main Agenda items may be made when that item is addressed by the City Council. As authorized by Section 551.071(2) of the Texas Government Code, this meeting may be convened into Closed Executive Session for the purpose of seeking confidential legal advice from the City Attorney on any agenda items listed herein. AGENDA MEMO (6/27/06 AGENDA) DATE: June 22, 2006 TO: Honorable Mayor and Council FROM: Robbie Corder, Assistant to the Director of Public Works SUBJECT: TXU Transmission Line Feasibility Study: Special Meeting June 27 ITEM: In the summer of 2005, TXU Electric Delivery representatives informed the City of plans to employ a contractor to locate overhead utility services and underground gas, water and sewer lines in the alley between Stanford and Amherst. In addition to the survey work, the company told City representatives that a second contractor would be performing soil tests at various locations in the alley. According to the utility, both contractor efforts were needed in order to initiate design related to the reconstruction of the electric transmission line located there. In notifying the City of the need to upgrade the line, TXU Electric Delivery noted it was also the company’s intention to install shielding to protect against lightning strikes to further improve the line’s reliability. Therefore, the preliminary design for the rebuild included taller, metal poles. In response to concerns expressed by residents and the City, the City appointed a citizen steering committee to work with TXU in developing rebuild alternatives for the transmission line. Additionally, the City initiated a study with Sega, Inc. to explore the feasibility of placing the transmission line underground, and placing all overhead utilities (i.e. telephone, cable, and electric distribution) underground. Sega was also directed to explore above ground alternatives, to include replacing the existing wood pole with similar wood poles. Representatives from Sega will be in attendance to present the findings of the report to the City Council and public. It is the City’s intention to ask the steering committee to host a community forum to garner citizen input regarding the available options based upon the study results from Sega. Subsequently, the steering committee will be asked to develop a recommendation for City Council consideration. RECOMMENDATION: ATTACHMENTS: 3800 UNIVERSITY BOULEVARD UNIVERSITY PARK, TEXAS 75205 TELEPHONE (214) 363-1644 C:\Documents and Settings\nwilson\Local Settings\Temporary Internet Files\OLK31\AGENDAMEMO (11) (2).doc 1:36 PM 06/22/06 TABLE OF CONTENTS Page No. SECTION 1 INTRODUCTION 1-1 SECTION 2 EXECUTIVE SUMMARY 2-1 SECTION 3 OVERHEAD TRANSMISSION ALTERNATIVES 3-1 SECTION 4 UNDERGROUND TRANSMISSION ROUTES 4-1 SECTION 5 CONVERSION OF ALLEY AERIAL SERVICES TO UNDERGROUND 5-1 SECTION 6 CONCLUSIONS 6-1 City of University Park, Texas - Sega Project No. 06-0069 i - 138-kV Underground Transmission Feasibility Study SECTION 1 INTRODUCTION INTRODUCTION The City of University Park, Texas has contracted with Sega Inc. to provide a feasibility study for undergrounding an existing aerial 138-kV transmission line and for undergrounding all existing aerial utility lines. Various alternatives for replacing the line with new overhead construction as well as installing the transmission line underground are considered. The Sega project team met with City staff, representatives of the various entities responsible for the affected utilities, and representatives of the Transmission Line Steering Committee in March 2006. After discussions, this Study was developed taking into consideration input from the interested parties and the various alternatives; then, preliminary opinions of probable cost were developed. A draft study was prepared sent to the City for review and a discussion was held in May 2006 with City Council members, City staff, and members of the Transmission Line Steering Committee. The Sega project team includes utilizing the services of Power Delivery Consultants, Inc. for the underground transmission considerations due to the highly-specialized nature of underground high-voltage systems. This Study is intended to provide the City of University Park, Texas and the Steering Committee information to assist in determining the alternative that fits their needs for the transmission line replacement. City of University Park, Texas 1 - 1 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study SECTION 2 EXECUTIVE SUMMARY EXECUTIVE SUMMARY This Study includes three primary sections which include determining various alternatives and opinions of probable costs for replacing the existing Greenville - Loma Alto 138-kV transmission line with overhead construction, placing the 138-kV transmission line underground, and placing existing overhead electric distribution, cable TV, and telephone utilities underground along the transmission line route. The resulting alternatives and opinions of probable costs are tabulated at the end of this summary. The overhead transmission alternatives include replacing the transmission line with new equipment and materials using the existing design, replacing the line with skip-span construction, replacing the line pole for pole (two alternatives with different conductor spacing, shorter spans, and shorter poles), and replacing the line without underbuilt electric distribution, cable TV, and telephone wires. Opinions of probable costs are developed . The underground transmission briefly describes the various types of underground transmission circuits, selects the most desirable for this application, and develops opinions of probable cost for construction. Two alternative routes are considered: Placing the line under the alley and routing it in one of the adjacent streets. Opinions of probable costs were developed for these alternatives. The third primary section of the Study concerns the conversion of alley aerial services to underground. Two variations of this conversion are shown. The first places the electric distribution, cable TV, and telephone underground in the alleys along the transmission line route. This alternative was considered to be constructed in conjunction with the City rebuilding/replacing the sanitary sewer, water lines, and the existing gas lines. Additional rights-of-way and easements would need to be obtained. A variation of this places the electric distribution, cable TV, and telephone service feeds at the front of the residential lots to avoid obtaining backyard rights-of-way which would be very difficult. This would actually require, possibly, more rights-of-way than the alley construction, but would generally be in less congested (but more visible) areas. Opinions of probable costs were developed for the undergrounding construction as well as obtaining rights-of-way. Table 6-1 is as included in the Section 6 - Conclusion. It summarizes the various combinations of alternatives ranging form rebuilding the existing 138-kV transmission line to placing all utilities (transmission, distribution, cable TV, and telephone) underground. City of University Park, Texas 2 - 1 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study SECTION 3 OVERHEAD TRANSMISSION ALTERNATIVES OVERHEAD TRANSMISSION ALTERNATIVES TXU Delivery (TXU) owns a 138-kV transmission line which passes through University Park, Texas. The line interconnects the TXU Greenville Substation located southeast of University Park with the Loma Alto Substation located southwest of University Park. The majority of the line passes through University Park alleys. The line is constructed on wood poles. In addition to the transmission circuit, the poles also carry a three-phase distribution primary circuit, single-phase secondaries, and telephone and CATV circuits. Span lengths average 138 feet. TXU intended to upgrade the line in such a manner that would result in taller poles, as discussed below. However, the public has expressed that taller poles are not acceptable and has expressed a desire that the transmission line be placed underground. Further, a University Park master plan from 1989 set out a program of City-wide alley improvements that would place all overhead utilities underground. While the City has undertaken alley improvements under a “mile-a-year” program, those improvements have been limited to replacing underground pipes (water, sewer, and gas) and paving, but not overhead utilities. It is not clear if the master plan intended for the transmission line to be placed underground. Underground transmission is rarely constructed because of the high costs, whereas distribution lines and communication lines are routinely undergrounded. The transmission line was constructed in 1969. While TXU has replaced deteriorated poles from time to time over the years, the poles, taken as a whole, are in poor condition today. Many are bowed and lean precariously (Figure 3-1). The poles are frequently struck by passing vehicles, especially large trucks. In fact, steel plates have been installed on many poles to protect them from vehicle strikes. City of University Park, Texas 3 - 1 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Figure 3-1 - Existing Transmission and Distribution Line TXU originally proposed to upgrade the existing Greenville - Lomo Alto 138-kV transmission line by replacing every other pole with a new steel transmission pole. The intermediate poles would be cut off above the distribution circuit. (Presumably, any defective intermediate poles would also be replaced.) Because of public objection to the proposed heights of the poles, TXU then proposed to replace every pole with a transmission pole, thereby reducing the pole heights by about 5 feet. Figure 3-2, prepared by TXU, is a visual comparison of the existing line with a simulation of the line with all poles replaced. Figure 3-2 - TXU Comparison of Existing and Proposed Transmission and Distribution Lines City of University Park, Texas 3 - 2 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study With TXU’s proposed construction, there are two reasons why the replacement poles must be taller than the existing structures: 1. The existing line was constructed with no overhead ground wire (OHGW) to protect (shield) it from lightning strikes. We are not sure why the line was not shielded, as virtually all transmission lines built in 1969 and since are shielded. In any case, the line is susceptible to lightning outages. TXU has added lightning arresters at several locations to the line. Even with the arresters, TXU reports that the line experienced three lightning outages during 2005. (A common design criteria for transmission lines is that a line should not experience more than one outage per year per 100 miles of line. For the Greenville - Lomo Alto line, which is about 3.5 miles in length, under this criteria, the line would not be expected to experience a lightning-caused outage more than once every 28 years on average.) To add an OHGW to a transmission line, additional pole top is needed above the conductors. In this case, 12-1/2 feet of additional pole is needed if the OHGW were attached to the pole. As an alternative, the additional pole top can be reduced if the OHGW is supported by a steel arm mounted at the top of the pole. With the steel arm, the additional pole needed above the conductors is reduced to 6 feet. 2. The existing line was configured with the three transmission wires in a “starburst” configuration. Two wires are supported by post insulators mounted to the top of the pole in a horizontal orientation both left and right of the pole. The third wire is supported by a post insulator mounted to the top of the pole in a vertical orientation. There is no way to accommodate the vertical post when upgrading with an OHGW. Whereas the vertical spacing between the top and bottom transmission wires was about 6 feet with the original design, the spacing between the top and bottom wires must increase to 14 feet with the new design. ALTERNATIVE OVERHEAD ROUTES Sega investigated alternate routes to the existing Greenville - Lomo Alto transmission line. Any alternate route in University Park would have to go down east-to-west city streets or alleys. We see no advantage to placing the line on an alternate University Park street or alley. The purpose of the Greenville - Lomo Alto transmission line is to provide a second feed to the Lomo Alto substation. If a second feed could be provided to Lomo Alto from another source, the Greenville - Lomo Alto line could possibly be eliminated. Such a source was identified as the North Haven Substation, located approximately three miles north of Lomo Alto near the Dallas Tollway. Sega investigated the possibility of the Lomo Alto - North Haven transmission City of University Park, Texas 3 - 3 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study line. While it appears that the line could be placed on public (tollway) right-of-way part of the way, it is evident that a significant part of the line would require easements along private residential properties. It is believed to place a transmission line on one set of residences, so as to eliminate an existing transmission line from a second set of residences, would not be politically possible. ALTERNATIVE OVERHEAD OPTIONS Sega investigated various alternatives for the overhead transmission line. The first alternative is a reconstruction of the line using the same configuration as now exists. (In order to improve lighting performance, all insulators will be equipped with lightning arresters. The existing line has had arresters added only at selected locations.) The remaining transmission alternatives add one or two overhead ground wires for lightning protection. As a basis of comparison, the two TXU proposed configurations are being evaluated (even though the public has expressed disapproval). Selection of Pole Type The line can be constructed with either steel or wood poles. From an engineering standpoint, either is acceptable. The diameters of wood and steel poles are nearly the same for poles of equivalent size and strength. Wood poles come in various shades of brown, depending on the type of preservative treatment specified. Steel poles are usually furnished with either galvanized coating (light gray) or weathering steel (dark brown). Selection of the color or "look" of the pole is one of personal preference. Some prefer the brown look, perhaps because they more resemble trees. Others prefer the look of galvanized poles because they tend to blend into the sky. We make no recommendation as to type or color of the poles as this value judgment is to be made by TXU and the City. Wood poles have two disadvantages as compared to steel poles: 1. Wood poles deteriorate over time due to fungal and insect activity. 2. Wood poles can warp or decay over time, as has been the case with the existing line. City of University Park, Texas 3 - 4 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study The wood poles are pressure treated when new to protect against fungal and insect decay, but that treatment dissipates over time. Wood poles are, typically, inspected and given ground-line treatment on a regular cycle (typically every 10 years) to extend the longevity of the pole, but interim replacements due to decay are typical after several years. Similarly, direct-embedded steel poles are given protection against ground-line corrosion by application of corrosion sleeves and a polymeric coating (similar to that used for pipelines) at and below the ground line. Steel poles are periodically inspected to assure that galvanic corrosion is not a problem, but, if so, sacrificial anodes are installed to arrest the corrosion. Also, after many years, the zinc coating on galvanized poles can become depleted, requiring painting of the poles. Properly maintained steel poles should not need interim replacements. The relative pricing between wood, galvanized, and weathering steel poles varies with the market. Right now, the purchase cost of wood holds an advantage over equivalent steel poles. However, the installation costs of wood poles are much heavier to handle than steel poles. Steel poles of the sizes used here are furnished in two pieces, facilitating improved maneuverability in the narrow alleys. Also, right now, weathering steel poles are less expensive than galvanized poles, as the price of zinc has skyrocketed in recent months. The opinions of probable costs contained herein are based on galvanized steel poles, but our opinion is that the selection of wood or weathering steel poles would not significantly alter the probable costs, especially since market conditions are less likely to change between now and the time of construction. Lightning Protection A transmission line cannot be protected against lightning strikes. However, there are two methods used to deal with the strikes that hit the line. The most common method is to install one or more overhead ground wires (shield wires) at the top of the structure to intercept the lightning stroke and carry the energy to the ground where it is dissipated. In this way, the flow of current in the current-carrying conductors is not interrupted and dangerous electrical surges do not stress electrical equipment at the substations. Another way to deal with lightning is to install lightning arresters. This is most often done as a remedy to existing lines that have experienced excessive lightning outages due to nonexistent or ineffective shielding. The arrester does not prevent the lightning stroke from hitting the current-carrying conductors, but is City of University Park, Texas 3 - 5 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study designed to absorb the bulk of the stroke energy and carry it to the ground for dissipation. This reduces the surge voltage at the electrical equipment. There is one manufacturer of transmission line arresters. According to the manufacturer's information, effective lightning protection is accomplished when arresters are applied to all current-carrying conductors at every structure. The usual application is to install the arresters in parallel with the insulators. TXU has installed arresters to some, but not all, of the existing structures. As mentioned earlier, TXU has experienced lightning-caused outages even after application of the arresters. The one alternative discussed here, where an overhead ground wire is not used, is based on installing arresters at all insulators. The Alternative Options Alternative 1 is the existing configuration, but with the pole structures replaced with new materials. In addition, lightning arrestors would be added to all insulators. With this alternative, most poles would remain the same height as now exist. Figure 3-3 shows the current configuration. The pole is shown as 57 feet above ground. Most of the existing poles are 57 or 52-1/2 feet above ground with a few as short as 48 feet and a few as tall as 70 feet above ground. Alternative 2 is the original TXU proposal where every other pole would be replaced with a new transmission pole. The intermediate poles would be cut off above the distribution primary and the transmission conductors would span over them. The advantage of this “skip span” construction is that fewer poles would have to be replaced and longer spans are more economical for transmission line construction. Figure 3-4 illustrates the pole configuration of Alternative 2. Figure 3-5 shows the configuration of the intermediate distribution poles based on current TXU standards. Alternative 3 is the same as Alternative 2, except every pole would be replaced with a new transmission pole. The advantage of this alternative is that the poles would be about 5 feet shorter. The disadvantage is increased cost. Also, some would consider the “picket fence” effect to be less attractive. Alternative 4 is similar to Alternative 2, except the middle transmission insulator and conductor are mounted on the opposite side of the pole from the top and bottom insulators. This is shown by Figure 3-6. The advantage of this “delta” configuration is that the pole height is reduced by 7 feet. Disadvantages are that the middle insulator and conductor overhang yards and would be more troublesome to maintain. Also, a second OHGW and support arm must be added, increasing the cost. City of University Park, Texas 3 - 6 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Alternative 5 is to remove all under-build circuits and place them underground as promulgated by the 1989 master plan. This would leave only the transmission circuit. Without the undercircuits, the poles can be shorter. Figure 3-7 illustrates the pole configuration for Alternative 5. Alternative 6 is to remove the transmission line, but leave the undercircuits. The transmission line would be built underground as explained elsewhere. The poles would be cut off above the distribution primary and the undercircuits would be left as is. Figure 3-5 illustrates the typical distribution pole without the transmission circuit. Alternative 7 is to remove all overhead circuits and the supporting structures. Those circuits will be placed underground as explained elsewhere. Figure 3-8 shows the various overhead options side-by-side. Table 3-1 is a summary of the alternative overhead options. Tables 3-2 through 3-7 are estimates of probable costs of the various overhead alternatives. City of University Park, Texas 3 - 7 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Table 3-2 University Par k Overhead Transmission Line Cost Estimate Alternative 1 - "Status Quo Configuration" Upgrade 1-Circuit 138-kV Transmission Circuit Install Arrestors at all Insulators Transfer 3-Phase Distribution Primary Underbuild Transfer 1-Phase Distribution Secondary Transfer Telephone and CATV Underbuilds Tubular Steel Transmission Poles 125-foot Transmission Spans 2.72 Mile Length 5/19/2006 0:00 Material MaterialLabo+ LaborExtended r UnitUnitQuantityUnit PriceUnit PriceUnit PricePrice Transmission Circuit Remove Existing Transmission Poleea111$0$3,000$3,000$333,000 Tangent Steel Pole (65'-1)ea111$3,254$6,508$9,762$1,083,582 Deadend Steel Poleea4$26,278$26,278$52,556$210,224 Deadend Foundationsea4$50,000$50,000$200,000 Transfer 636 kcmil ACSR Rookft43110$0$5$5$215,550 138-kV Post Insulator Assemblyea445$700$535$1,235$549,575 138-kV Strain Insulator Assemblyea24$643$715$1,358$32,592 138-kV Arrestorsea469$600$200$800$375,200 138-kV Jumper Postsea12$462$535$997$11,964 Mounting Bolts and Nuts,1 Lotea1$5,500$0$5,500$5,500 Pole Groundingea55$50$350$400$22,000 $3,039,187 Distribution and Communication Circuits Cut Tops for Intermediate Distribution Poles ea0$0$0$0$0 Primary Crossarms for New Polesea111$150$90$240$26,640 Neutral Attachments for New Polesea111$40$30$70$7,770 Secondary Attachments for New Polesea111$40$30$70$7,770 Telcommunication Attachments for New Polesea222$40$30$70$15,540 Transfer 3-Phase Primaryft43110$0$5$5$215,550 Transfer Neutralft14370$0$5$5$71,850 Transfer Secondaryft14370$0$5$5$71,850 Transfer Telephoneft14370$0$5$5$71,850 Transfer CATVft14370$0$5$5$71,850 $560,670 Total Transmission + Distribution$3,599,857 Contingency 25%$899,964 Total$4,499,821 Table 3-3 University Par k Overhead Transmission Line Cost Estimate Alternative 2 - Vertical Configuration, Skip Span Upgrade 1-Circuit 138-kV Transmission Circuit Transfer 3-Phase Distribution Primary Underbuild Transfer 1-Phase Distribution Secondary Transfer Telephone and CATV Underbuilds Tubular Steel Transmission Poles 250-foot Transmission Spans Intermediate Wood Distribution Poles (Existing) 2.72 Mile Length 5/19/2006 0:00 Material MaterialLabo+ LaborExtended r UnitUnitQuantityUnit PriceUnit PriceUnit PricePrice Transmission Circuit Remove Existing Transmission Poleea55$0$3,000$3,000$165,000 Tangent Steel Pole (80'-1)ea55$4,782$9,564$14,346$789,030 OHGW Davit Armea55$100$50$150$8,250 Deadend Steel Poleea4$26,278$26,278$52,556$210,224 Deadend Foundationsea4$50,000$50,000$200,000 Install 3/8-inch OHGWft14370$0.5 $3.0 $3.5 $50,295 Transfer 636 kcmil ACSR Rookft43110$0$5$5$215,550 OHGW Suspension Assyea55$75$180$255$14,025 OHGW Deadend Assyea8$204$830$1,034$8,272 138-kV Post Insulator Assemblyea445$700$535$1,235$549,575 138-kV Strain Insulator Assemblyea24$643$715$1,358$32,592 138-kV Jumper Postsea12$462$535$997$11,964 Mounting Bolts and Nuts,1 Lotea1$5,500$0$5,500$5,500 Pole Groundingea55$50$350$400$22,000 $2,282,277 Distribution and Communication Circuits Cut Tops for Intermediate Distribution Poles ea56$0$500$500$28,000 Primary Crossarms for New Polesea55$150$90$240$13,200 Neutral Attachments for New Polesea55$40$30$70$3,850 Secondary Attachments for New Polesea55$40$30$70$3,850 Telcommunication Attachments for New Polesea110$40$30$70$7,700 Transfer 3-Phase Primaryft43110$0$5$5$215,550 Transfer Neutralft14370$0$5$5$71,850 Transfer Secondaryft14370$0$5$5$71,850 Transfer Telephoneft14370$0$5$5$71,850 Transfer CATVft14370$0$5$5$71,850 $559,550 Total Transmission + Distribution$2,841,827 Contingency 25%$710,457 Total$3,552,284 Table 3-4 University Par k Overhead Transmission Line Cost Estimate Alternative 3 - Vertical Configuration, Span-for-Span Upgrade 1-Circuit 138-kV Transmission Circuit Transfer 3-Phase Distribution Primary Underbuild Transfer 1-Phase Distribution Secondary Transfer Telephone and CATV Underbuilds Tubular Steel Transmission Poles 125-foot Transmission Spans 2.72 Mile Length 5/19/2006 0:00 Material MaterialLabo+ LaborExtended r UnitUnitQuantityUnit PriceUnit PriceUnit PricePrice Transmission Circuit Remove Existing Transmission Poleea111$0$3,000$3,000$333,000 Tangent Steel Pole (75'-1)ea111$4,400$8,800$13,200$1,465,200 OHGW Davit Armea111$100$50$150$16,650 Deadend Steel Poleea4$26,278$26,278$52,556$210,224 Deadend Foundationsea4$50,000$50,000$200,000 Install 3/8-inch OHGWft14370$0.5 $3.0 $3.5 $50,295 Transfer 636 kcmil ACSR Rookft43110$0$5$5$215,550 OHGW Suspension Assyea55$75$180$255$14,025 OHGW Deadend Assyea8$204$830$1,034$8,272 138-kV Post Insulator Assemblyea445$700$535$1,235$549,575 138-kV Strain Insulator Assemblyea24$643$715$1,358$32,592 138-kV Jumper Postsea12$462$535$997$11,964 Mounting Bolts and Nuts,1 Lotea1$5,500$0$5,500$5,500 Pole Groundingea55$50$350$400$22,000 $3,134,847 Distribution and Communication Circuits Cut Tops for Intermediate Distribution Poles ea0$0$0$0$0 Primary Crossarms for New Polesea111$150$90$240$26,640 Neutral Attachments for New Polesea111$40$30$70$7,770 Secondary Attachments for New Polesea111$40$30$70$7,770 Telcommunication Attachments for New Polesea222$40$30$70$15,540 Transfer 3-Phase Primaryft43110$0$5$5$215,550 Transfer Neutralft14370$0$5$5$71,850 Transfer Secondaryft14370$0$5$5$71,850 Transfer Telephoneft14370$0$5$5$71,850 Transfer CATVft14370$0$5$5$71,850 $560,670 Total Transmission + Distribution$3,695,517 Contingency 25%$923,879 Total$4,619,396 Table 3-5 University Par k Overhead Transmission Line Cost Estimate Alternative 4 - Delta Configuration, Skip Span Upgrade 1-Circuit 138-kV Transmission Circuit Transfer 3-Phase Distribution Primary Underbuild Transfer 1-Phase Distribution Secondary Transfer Telephone and CATV Underbuilds Tubular Steel Transmission Poles 250-foot Transmission Spans Intermediate Wood Distribution Poles (Existing) 2.72 Mile Length 5/19/2006 0:00 Material MaterialLabo+ LaborExtended r UnitUnitQuantityUnit PriceUnit PriceUnit PricePrice Transmission Circuit Remove Existing Transmission Poleea55$0$3,000$3,000$165,000 Tangent Steel Pole (75'-1)ea55$4,400$8,800$13,200$726,000 OHGW Davit Armea110$100$50$150$16,500 Deadend Steel Poleea4$26,278$26,278$52,556$210,224 Deadend Foundationsea4$50,000$50,000$200,000 Install 3/8-inch OHGWft28740$0.5 $3.0 $3.5 $100,590 Transfer 636 kcmil ACSR Rookft43110$0$5$5$215,550 OHGW Suspension Assyea110$75$180$255$28,050 OHGW Deadend Assyea16$204$830$1,034$16,544 138-kV Post Insulator Assemblyea445$700$535$1,235$549,575 138-kV Strain Insulator Assemblyea24$643$715$1,358$32,592 138-kV Jumper Postsea12$462$535$997$11,964 Mounting Bolts and Nuts,1 Lotea1$5,500$0$5,500$5,500 Pole Groundingea55$50$350$400$22,000 $2,300,089 Distribution and Communication Circuits Cut Tops for Intermediate Distribution Poles ea56$0$500$500$28,000 Primary Crossarms for New Polesea55$150$90$240$13,200 Neutral Attachments for New Polesea55$40$30$70$3,850 Secondary Attachments for New Polesea55$40$30$70$3,850 Telcommunication Attachments for New Polesea110$40$30$70$7,700 Transfer 3-Phase Primaryft43110$0$5$5$215,550 Transfer Neutralft14370$0$5$5$71,850 Transfer Secondaryft14370$0$5$5$71,850 Transfer Telephoneft14370$0$5$5$71,850 Transfer CATVft14370$0$5$5$71,850 $559,550 Total Transmission + Distribution$2,859,639 Contingency 25%$714,910 Total$3,574,549 Table 3-6 University Par k Overhead Transmission Line Cost Estimate Alternative 5 - Vertical Configuration, Under Circuits Removed Upgrade 1-Circuit 138-kV Transmission Circuit Distribution and Communication Circuits Removed 250-foot Transmission Spans 2.72 Mile Length 5/19/2006 0:00 Material MaterialLabo+ LaborExtended r UnitUnitQuantityUnit PriceUnit PriceUnit PricePrice Transmission Circuit Remove Existing Transmission Poleea111$0$3,000$3,000$333,000 Tangent Steel Pole (60-2)ea55$2,608$2,608$5,216$286,880 OHGW Davit Armea55$100$50$150$8,250 Deadend Steel Poleea4$26,278$26,278$52,556$210,224 Deadend Foundationsea4$50,000$50,000$200,000 Install 3/8-inch OHGWft14370$0.5 $3.0 $3.5 $50,295 Transfer 636 kcmil ACSR Rookft43110$0$5$5$215,550 OHGW Suspension Assyea55$75$180$255$14,025 OHGW Deadend Assyea8$204$830$1,034$8,272 138-kV Post Insulator Assemblyea445$700$535$1,235$549,575 138-kV Strain Insulator Assemblyea24$643$715$1,358$32,592 138-kV Jumper Postsea12$462$535$997$11,964 Mounting Bolts and Nuts,1 Lotea1$5,500$0$5,500$5,500 Pole Groundingea55$50$350$400$22,000 $1,948,127 Distribution and Communication Circuits Remove 3-Phase Primaryft43110$0$5$5$215,550 Remove Neutralft14370$0$5$5$71,850 Remove Secondaryft14370$0$5$5$71,850 Remove Telephoneft14370$0$5$5$71,850 Remove CATVft14370$0$5$5$71,850 $502,950 Total Transmission + Distribution$2,451,077 Contingency 25%$612,769 Total$3,063,846 Table 3-7 University Par k Overhead Transmission Line Cost Estimate Alternative 6 - Remove Transmission, Leave Under Circuits Remove 1-Circuit 138-kV Transmission Circuit Distribution and Communication Circuits Untouched 125-foot Spans 2.72 Mile Length 5/19/2006 0:00 Material MaterialLabo+ LaborExtended r UnitUnitQuantityUnit PriceUnit PriceUnit PricePrice Transmission Circuit Cut Top off Existing Transmission Poleea111$0$500$500$55,500 Remove 636 kcmil ACSR Rookft43110$0$5$5$215,550 $215,550 Contingency 25%$53,888 Total$269,438 Table 3-8 University Par k Overhead Transmission Line Cost Estimate Alternative 7 - Remove Overhead Lines in Entiret y Upgrade 1-Circuit 138-kV Transmission Circuit Distribution and Communication Circuits Removed 250-foot Transmission Spans 2.72 Mile Length 5/19/2006 0:00 Material MaterialLabo+ LaborExtended r UnitUnitQuantityUnit PriceUnit PriceUnit PricePrice Transmission Circuit Remove Existing Transmission Poleea111$0$1,000$1,000$111,000 Remove 636 kcmil ACSR Rookft43110$0$5$5$215,550 $326,550 Distribution and Communication Circuits Remove 3-Phase Primaryft43110$0$5$5$215,550 Remove Neutralft14370$0$5$5$71,850 Remove Secondaryft14370$0$5$5$71,850 Remove Telephoneft14370$0$5$5$71,850 Remove CATVft14370$0$5$5$71,850 $502,950 Total Transmission + Distribution$829,500 Contingency 25%$207,375 Total$1,036,875 SECTION 4 UNDERGROUND TRANSMISSION ROUTES UNDERGROUND TRANSMISSION ROUTES INTRODUCTION TXU Electric Delivery (TXU) is proposing to rebuild the 138-kV transmission line between its Greenville and Lomo Alto Substations using steel pole structures. As a result of concerns of some of the citizens of the City of University Park, Texas, Sega Inc. and its subcontractor, Power Delivery Consultants, Inc. (PDC), were commissioned to prepare underground transmission alternatives to the TXU proposed overhead line. This document describes preliminary designs and cost estimates for two underground transmission alternatives. PDC is an engineering services company that specializes in the design and specification of underground transmission lines. PDC has prepared cost estimates, completed preliminary designs, and provided specifications for six underground transmission lines in the State of Texas. These include the 8.5-mile, 138-kV XLPE underground transmission line between Port Isabel and South Padre Island and the relocation of 6 miles of two, 138-kV overhead transmission lines for widening of the Katy Freeway in Houston. TRANSMISSION LINE ALIGNMENTS The existing TXU Greenville - Lomo Alto 138-kV underground transmission line in the City of University Park is constructed on wood poles that are primarily located in alleys between residential streets. The existing wood poles support a 138-kV transmission line as well as a distribution line, pole-mounted distribution transformers, and some residential service cables. Early during the Study effort, Sega was informed that the City of Highland Park was considering replacing an underground water line that resides beneath Mockingbird Lane. This would require major excavation and disruption of traffic during construction. It was felt that, while such disruption was underway, it might be an opportunity to install underground cables coincident with the water line project. However, we understand that Highland Park has now decided not to excavate, but rather repair the water line in situ. There would, therefore, be no advantage to locating the underground line along Mockingbird as compared to any other east-to-west street in University Park. City of University Park, Texas 4 - 1 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study PDC considered the following two alternatives for constructing an underground transmission line to replace the existing 138-kV overhead transmission line. This document does not address the future disposition of the distribution lines on the wood poles. Existing Right-Of-Way The first underground alternative (UG1) that was investigated was to construct a 138-kV underground transmission line along the alignment for the existing 138-kV overhead transmission line. However, there are numerous challenges to construct a conventional open-trench underground transmission line down the narrow alley where the existing line is located. The following issues make this underground alternative difficult and expensive to construct. There are numerous underground utilities (i.e., sewer, gas, and water) in the alleys that would have to be relocated to excavate the transmission cable trench or the widths of the alleys would have to be increased to facilitate excavation of the cable trench. The widths of the existing alleys are too narrow to accommodate a conventional, open-cut cable trench. This being the case, the width of the alleys would have to be increased to the size of the existing utilities. More specifically, the increased right-of-way width would have to be on the side of the alley that is opposite from the existing wooden poles. Widening the alleys would require acquisition of property from local residents and existing structures would have to be relocated or modified in some cases. The seven or eight splice vaults for the underground transmission cables (typically 8-feet wide by 20-feet long by 7-feet high) would have to be located in the side streets for the majority of the existing alignment. Because of the above construction issues, the only technically feasible method of constructing the underground transmission line along the existing alignment would be to use a trenchless construction method called horizontal directional drilling (HDD). In this case, HDD rigs would bore beneath the existing utilities (20 to 30 feet below the surface) with splice vaults installed on side streets. Additional details of the HDD equipment and limitations are presented in a following section. Closest City Streets The second and preferred alternative (UG2) for constructing the underground transmission line is to construct the line in the closest City streets to the existing overhead transmission line. In this case, conventional open-cut excavation equipment (e.g., backhoes and/or trackhoes) would be used to excavate a City of University Park, Texas 4 - 2 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study trench along one of the closest City streets to the existing alignment and a concrete-encased duct bank would be installed to accommodate subsequent installation of the transmission cables. The seven or eight concrete vaults would be installed in the City streets for splicing of the transmission cables. UNDERGROUND TRANSMISSION TECHNOLOGIES Several cable system types could be used for the 138-kV underground transmission line: High-pressure, fluid-filled (HPFF); high-pressure, gas-filled (HPGF); extruded-dielectric (ED); and self-contained, fluid- filled (SCFF). These systems are described in the following sections. Extruded-Dielectric Cable, XLPE, and EPR ED cables have an extruded insulation that requires no pressurization. They can, therefore, be installed individually in plastic ducts, similar to distribution cables. ED cables with cross-linked polyethylene (XLPE) insulation are subject to “water trees” just as distribution cables are; therefore, the transmission cables always have a metallic moisture barrier. Lead is traditionally used and is considered the best material, but aluminum and copper moisture barriers and laminates of these materials are becoming common. Ethylene Propylene Rubber (EPR) insulation is installed without a moisture barrier because of its better resistance to damage from moisture. Ducts are typically PVC provided in 10-foot or 20-foot lengths, held in place with spacers and encased in concrete, but the duct size for a 138-kV cable is nominal 6 inches (6.625-inches OD) versus the nominal 5-inch ducts used for distribution cables. Transmission cables typically require thicker, Schedule 40 ducts. Figure 1 shows a 138-kV XLPE cable. Figure 4-1 - ED (XLPE) Insulated Cable City of University Park, Texas 4 - 3 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study High-Pressure, Fluid-Filled Cable Each cable consists of a conductor, typically copper, and has approximately 0.44 inches of insulation consisting of helically-applied paper tapes that are factory impregnated with a very high-viscosity, dielectric liquid. The three cables for the three-phase system are approximately 3- to 3.5-inches in diameter and are installed in a coated and cathodically protected 8-5/8-inch OD, 0.25-inch wall mild steel pipe. The pipe is provided in double-random lengths 45- to 55-feet long. Pipe ends are flared at the coating facility and backing rings are inserted to align the pipe ends in the field to provide a smooth inner profile and prevent weld slag from entering the pipe during welding. The welds are x-rayed and tested with a holiday detector after coating is applied in the weld area. After the three cables are pulled simultaneously into the pipe and spliced and terminations are installed, the pipe is evacuated and pressurized with a dielectric fluid (alkylbenzene or polybutene) to a nominal 200-psig pressure to maintain the electrical strength of the insulation. Figure 4-2 shows a pipe-type cable. Figure 4-2 - Typical Pipe-Type Cable High-Pressure, Gas-Filled Cable High-pressure, gas-filled (HPGF) cables have the same general construction as the HPFF pipe-type cable, except that the pipe is filled with dry nitrogen gas pressurized at 200 psig. The insulation thickness is slightly thicker (0.5 inch) for this type of cable system. Self-Contained, Fluid-Filled (SCFF) Cable The cables have copper conductors with hollow cores through which dielectric liquid is passed to pressurize the wrapped paper insulation. The cables are installed individually in plastic ducts. This type is seldom used on land cables (it is very common on submarine cables) and was not evaluated for this Study. City of University Park, Texas 4 - 4 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Figure 4-3 - Typical SCFF Cable Advantages and Disadvantages of Each Cable Type Advantages Disadvantages Insulation thickness slightly greater and HPFF Proven, reliable system; in service at 138-kV •• 70 years ampacity slightly lower than SCFF system Steel pipe provides good mechanical • protection Specialized equipment needed for installation • Lower magnetic fields than other cable types and repair • Can be installed somewhat more quickly Electrical losses and charging currents higher •• than ED cables than for ED cables Ratio of normal-to-emergency ampacity Restoration time is longer than ED •• typically higher than for XLPE or EPR cables U.S. supplier and several U.S. installers • ED No dielectric fluid or fluid pressurizing Splices and terminations have been a problem •• equipment is required in some cases Less complex cable system Less forgiving of defects in manufacturing/ •• Lower dielectric losses and VARS than installation • HPFF cable Necessary to have splices and terminations • No special precautions for circuit restoration supplied by the cable supplier and preferably • Installation can use same equipment as installed by cable factory technicians. • distribution cables Complex sheath bonding methods; sheath • More than a dozen suppliers world-wide voltages can be a problem • (and a U.S. supplier) SCFF Proven, reliable system, in service at 138-kV Most complex of the cable systems •• • for 70 years Highest maintenance No domestic suppliers • City of University Park, Texas 4 - 5 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study University Park Application The project team selected the ED cable (XLPE insulation) system to be the best transmission cable technology for the City of University Park underground transmission line alternative. We believe that an XLPE transmission cable system is best suited for this application for the following reasons: 1. It currently is the most common type of 138-kV transmission cable system being installed in the U.S. and most other places in the world. 2. Minimal space is required for overhead-to-underground transitions. One of the most common ways of making overhead to underground transitions for XLPE cable systems are pole-mounted terminations as shown in Figure 4-4. Overhead-to-underground transitions for HPFF cable installations are generally constructed by ground-level, fenced-in areas similar to a small substation. Usually, at least one of the two ends is terminated in a substation because a fluid pressurization unit is required. 3. Minimal maintenance is required for this type of cable system. Figure 4-4 - Typical Overhead-to-Underground Transition for 138-kV XLPE Cable System TXU has both HPFF and XLPE transmission cables at different locations on its transmission system and indicated that it would consider either type (HPFF or XLPE) of transmission cable as underground alternatives for the Greenville - Lomo Alto line. City of University Park, Texas 4 - 6 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study DESIGN REQUIREMENTS A preliminary underground transmission cable system design was completed prior to preparing cost estimates for the two underground system alternatives. The technical design requirements that were assumed for the underground transmission alternatives were: 1. Transmission Capacity: The electric-power transmission capacity of the underground transmission line must be equal to the power transmission capacity of the overhead transmission line alternatives. The largest conductor size that can be supported by steel pole replacements for the wood poles would be 795 kcmil ACSR. The current-carrying rating of this type of conductor and typical span lengths would be approximately 1,000 amperes. For underground transmission systems, the 24-hour load factor (a measure of daily load variability) is an important design parameter. PDC assumed a 24- hour load factor of 75 percent based on typical underground transmission line design criteria provided by TXU (Lemmon Avenue Substation Underground Transmission Project). 2. 138-kV XLPE Transmission Cables: The XLPE transmission cable technical specifications provided by TXU were used for the preliminary design. TXU’s specifications for 138-kV transmission cables is a lead-sheath cable with 0.850-inch thick XLPE insulation that comply with U.S. industry specifications for this type of cable (AEIC CS7-93 - Specifications for Cross-Linked, Polyethylene, Insulated, Shielded Power Cables Rated 69 through 138 kV). AEIC CS7-93 specifies a maximum conductor temperature of 90 degrees C for normal operating conditions. 3. Cable System Grounding: XLPE transmission cable system sheaths are typically grounded using special methods to minimize induced sheath currents. These special bonding methods to reduce induced sheath currents result in induced sheath voltages. TXU’s specifications require that the induced sheath voltages do not exceed 150 volts during normal operating conditions. This requirement is one constraint that determines the maximum distance between cable manholes (splice vaults). 4. Cable Pulling Tensions and Sidewall Bearing Pressure: Other design constraints are the maximum pulling tension that can be applied to the cables during installation and the maximum pressure applied to the cable as it is pulled around bends in the duct bank. These constraints also limit the maximum distance between splice vaults. AEIC G1 recommendations for maximum pulling tension and sidewall bearing pressure were taken into account when performing preliminary design calculations for the underground transmission alternatives. CONSTRUCTION METHODS Construction methods assumed for the two underground alternatives are described in the following sections. City of University Park, Texas 4 - 7 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Horizontal Directional Drilling (UG1 ) As discussed in Section 2, HDD is the only feasible method for installing underground transmission cables along the alignment for the existing 138-kV transmission line. This is due to the narrow alleys and existing underground utilities. Figure 4-5 shows a typical cross section of a 138-kV XLPE transmission line using HDD boring. The 28-inch diameter bore would be constructed at a depth of 25 to 35 feet below the surface of the ground, depending on the mechanical properties of the soil along the transmission line alignment. The next step in the HDD process is to drill a pilot hole and then back-ream the pilot bore to expand the bore diameter to 28 inches (Figure 4-5). Set-up areas for the drilling rigs must be large enough to accommodate the equipment for containing and processing the drilling mud (water/bentonite slurry). The next step in the construction process (Figure 4-6) is to assemble strings of the HDPE pipes that are long enough to be pulled into the entire length of the bore and pull them into the bore. City of University Park, Texas 4 - 8 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Transmission Cable 28-inch ö HDD Bore Drilling Mud and Soil 6-inch SDR 11 HDPE Pipe Figure 4-5 - HDD Bore Cross Section Figure 4-6 - HDPE Pipe Strings HDD rigs (Figure 4-7) are available that can be used to construct bores several feet in diameter for bore lengths over one mile; however, they require a large amount of area (i.e., 100 by 150 feet) to accommodate auxiliary equipment, such as drilling mud processing and storage equipment, cranes, and stockpiles of drill pipe. Another limitation for XLPE underground transmission cables is the maximum cable pulling length of approximately 3,000 feet. City of University Park, Texas 4 - 9 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Figure 4-7 - Large HDD Boring Rig Used for 3,500-Foot Bore The set-up area for midi-size HDD rigs (Figure 4-8) and auxiliary equipment could be accommodated on side streets for the City of University Park underground Alternative 1, but the maximum bore length for a 28-inch diameter bore is approximately 1,200 to 1,300 feet, depending on soil conditions. Figure 4-8 - Midi-Size HDD Boring Rig Used for 1,200-Foot Bore City of University Park, Texas 4 - 10 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Concrete-Encased Duct Bank Construction (UG2) XLPE transmission cable underground transmission lines are typically constructed in urban and suburban environments using concrete-encased duct banks (see Figure 4-9). Figure 4-9 - Typical XLPE Transmission Cable Duct Bank Installation Concrete-encased duct banks are typically used in City streets because the length of open trench at any one time during construction can be limited to 300 or 400 feet. The transmission cables are then installed after the duct bank construction and splice vault installation have been completed. Concrete-encased duct banks also provide good mechanical protection against dig-ins after they have been placed in service. Figure 4-10 shows a trench cross section for the street construction alternative (UG2). City of University Park, Texas 4 - 11 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Figure 4-10 - Trench Cross Section for Street Construction (UG2) City of University Park, Texas 4 - 12 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Transmission Cable Splice Vaults City of University Park Power Delivery Consultants, Inc. The transmission cable splices for both alternatives would be installed in pre-fabricated concrete vaults approximately 20-feet long, 7-feet wide, and 7-feet high (see Figures 4-11 and 4-12). Figure 4-11 - Concrete Splice Vault 7' 7' Figure 5-5. Trench cross section for street construction (UG2) Figure 4-12-Pre-fabricated Concrete Splice vaults City of University Park, Texas 4 - 13 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study CABLE INSTALLATION The cables are shipped to the construction site on large reels that are approximately 12-feet high by 8-feet wide and pulled into the cable ducts or HDPE pipes one at a time (Figure 4-13) with a cable winch (Figure 4-14) at the opposite end of the cable duct. Figure 4-13 - Cable Pulling Into Concrete-Encased Duct Bank Figure 4-14 - Cable Pulling Wench City of University Park, Texas 4 - 14 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study The cable splicing activities (Figure 4-15) at each of the manholes takes approximately one week. Figure 4-15 - Cable Splicing in Concrete Vault UNDERGROUND ALIGNMENTS The alignments for the two underground transmission alternatives roughly follow the path of the existing overhead transmission line from the eastern City limit at the North Central Expressway to the western City limit at the North Tollway where the existing line turns south to the Lomo Alto substation. It was assumed that overhead-to-underground transitions (riser poles) would be installed at both of these locations. Additional details of the two underground alternatives that were selected by the Sega/PDC team are given in the following sections. Existing Right-of-Way The eastern overhead-to-underground transitions would occur at a small park located at the intersection of Willard and Daniel (Figure 4-16). City of University Park, Texas 4 - 15 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Figure 4-16 - Proposed Location for Eastern Overhead-to-Underground Transition City of University Park, Texas 4 - 16 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Splice Vault Stanford Amherst Figure 4-17 - Alignment for Underground Alternative 1 (UG1) The alignment for this option would proceed from east to west as follows: 1. The first section of the alignment would be concrete-encased duct bank from the riser pole to the eastern end of the alley between Daniel and Rosedale (approximately 200 feet). 2. The transmission cables would then be installed beneath the alley (between Daniel and Rosedale) using HDD with the bore machine set up in the small park shown in Figure 4-17. The opposite end of the HDD bore and first manhole would be located in the street at Boedeker. This is a distance of approximately 1,100 feet. 3. The underground transmission line would then turn 90 degrees to the north and proceed to the alley between Amherst and Stanford. It would be installed beneath the surface of Boedeker Street in a concrete-encased duct bank using conventional open-cut excavation, except where it crosses Lovers Lane. A construction method called pipe jacking and boring would be used to install a steel casing or reinforced concrete pipe (RCP) beneath Lovers Lane to avoid disruption of the traffic of this relatively busy street. 4. The alignment would turn 90 degrees to the west at the alley between Amherst and Stanford. The underground transmission line would then follow the existing transmission line route from Boedeker to Lomo Alto where it would return to overhead construction via a second riser pole. The underground transmission cables would be installed beneath the alley located between Amherst and Stanford using HDD. This distance of approximately 2.1 miles would be traversed by means of 10 bores shown in Table 3-1 with six manholes located on the side streets. City of University Park, Texas 4 - 17 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Number End 1 End 2 Distance (ft) 1 Boedeker Durham 945 2 Durham Airline 775 3 Airline Hillcrest 1,185 4 Hillcrest Dickens 915 5 Dickens Thackery 730 6 Thackery Baltimore 1,130 7 Baltimore Tulane 1,130 8 Tulane Preston 1,130 9 Preston Douglas 1,290 10 Douglas Lomo Alto 1,230 Table 4-1 - HDD Bores between Boedeker and Lomo Alto City of University Park, Texas 4 - 18 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study The number of HDD bores could be significantly reduced if there were space to set up the full-size HDD boring machines. However, the side streets along the alignment are only wide enough to accommodate the midi-size HDD rigs shown in Figure 4-7 and the maximum distance for this type of rig is approximately 1,200 to 1,300 feet. There would be a total of seven splice vaults for the above underground alignment. Several of the shorter bores would be connected without splice vaults. Closest City Streets The second underground alternative (UG2) would start at the same overhead-to-underground transition location as the first underground alternative (see Figure 4-17 and Figure 4-18). Splice Vault Stanford Amherst Lovers Lane Rosedale Daniel Figure 4-18 - Alignment for Underground Alternative 1 (UG2) City of University Park, Texas 4 - 19 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study The underground transmission line would then be constructed in City streets as follows: 1. The cables would be installed in concrete-encased duct bank from the riser pole in the small park to Rosedale where it would turn west. 2. The concrete-encased duct bank would then proceed west along Rosedale to Boedeker where it would turn north on Boedeker. 3. The cable duct bank would then follow Boedeker to Stanford where it would turn 90 degrees to the west. As in the previous underground alternative, pipe jacking and boring would be used to install the cables in a steel casing beneath Lovers Lane. 4. The cable duct bank would then follow Stanford to Lomo Alto where a transition would be made from underground construction to overhead construction at a second riser pole. The cable duct bank would be installed with a minimum cover of 36 inches for the majority of the alignment. There are six locations where the duct bank will have to dip beneath existing storm and sanitary sewers. The deepest of these is between Tulane and Baltimore where a 15-inch sanitary sewer is installed below a large box culvert storm sewer. The cable duct bank would have to dip below both of these facilities with a depth to the top of the duct bank of 14 feet. The underground alignment for this alternative between Boedeker and Lomo Alto could be constructed along Amherst rather than Stanford. There would be eight manholes for the above underground transmission alignment. The second UG (i.e., closest City streets) is the favored alternative because: 1. There are very few underground utilities located in Stanford and Amherst. 2. It is less expensive to construct concrete-encased duct bank compared to the HDD. 3. There are fewer construction uncertainties with conventional open-cut construction compared to HDD construction. City of University Park, Texas 4 - 20 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study CABLE SIZING Ampacity calculations were performed to determine the cable conductor sizes that will be necessary to achieve an ampacity rating of 1,000 amperes for the two underground transmission alternatives. The design parameters shown in Table 4-2 were used to perform the ampacity calculations. Parameter Value Units 24-Hour Load Factor 75 Percent Native Soil Thermal Resistivity 70 °C - cm/W Maximum Soil Ambient Temperature at 6-Foot Depth 25 °C Maximum Soil Ambient Temperature at 30-Foot Depth 22 °C Concrete-Encasement Thermal Resistivity 60 °C - cm/W HDD Grout Thermal Resistivity 80 °C - cm/W Maximum Conductor Temperature, Normal Operation 90 °C Maximum Conductor Temperature, Emergency Operation 105 °C Burial Depth (Top of Duct Bank) 3 to 9 ft Burial Depth (Top of HDD Bore) 25 to 35 ft Cross-Bonding Cable Sheath Bonding -- and Single-Point Table 4-2 - Ampacity Calculation Parameters Results of the ampacity calculations are shown in Table 4-3. Copper Depth Conductor Ampacity Conductor Size Construction (ft)Stranding(A) (kcmil) Compressed 2x2 Duct Bank 4 1,750 1,118 Concentric Compressed 2x2 Duct Bank 9 1,750 1,060 Concentric Compact 2x2 Duct Bank 9 1,750 1,133 Segmental Compressed 2x2 Duct Bank 14 1,750 1,038 Concentric Compact 2x2 Duct Bank 14 1,750 1,104 Segmental Compressed HDD HDPE Pipe 30 1,750 987 Concentric Compact HDD HDPE Pipe 30 1,750 1,054 Segmental Table 4-3 - Results of Ampacity Calculations City of University Park, Texas 4 - 21 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study In summary, the ampacity calculations indicate that a 1,750 kcmil compressed round copper conductor will meet the 1,000-ampere ampacity target at all locations for the concrete-encased duct bank UG2 alternative. A 1,750-kcmil compact segmental copper conductor will be required to meet the ampacity requirement for the HDD (UG1) installation alternative. The segmental conductor increases the cable rating by reducing skin effect losses. OPINION OF PROBABLE COSTS Probable costs were prepared for both underground cable system alternatives based on PDC’s observations from several recent XLPE transmission cable projects. Details of the probable costs are shown at the end of this Section. The following assumptions were made in preparing probable costs for the 2.7-mile long underground transmission line: 1. A single contract would be issued to engineer, procure, and construct (EPC) the underground transmission line. It is common for utilities to award a single EPC or turn-key contract to a transmission cable construction company or cable company to take full responsibility for the design, supply of material, and construction of the underground transmission line. 2 No right-of-way or easement costs are included. It is assumed that the underground transmission line will be constructed on the existing right-of-way for the overhead line or that the City of University Park will issue easements where the underground lines are constructed in City streets. Any fees that are required to extend the existing right-of-way agreements for underground constructions should be added to the probable costs in this document. 3. Cable and accessory costs are based on current typical costs for this equipment and PDC’s estimate of the costs during the next 12-month period. It should be noted that the cost of transmission cable and, to a lesser extent, transmission cable accessories fluctuate significantly, depending on the cost of metals, other market conditions, and foreign currency exchange rates. 4. No TXU engineering costs are included. TXU or TXU’s subcontractor would be responsible for reviewing the EPC contractor’s detailed design calculations, construction drawings, as-built drawings, and other project documentation. 5. No TXU field construction inspection costs are included. TXU or TXU’s subcontractor should perform construction inspection to insure that the underground transmission line is constructed in compliance with the project specifications. City of University Park, Texas 4 - 22 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study 6. The costs do not include the costs to solicit and evaluate EPC proposals for the lines. 7. The costs do not include the cost of performance or warranty bonds. 8. The costs do not include the cost of decommissioning of the existing overhead line. Costs for construction of the underground transmission line include the following: 1. Materials required to construct the underground transmission line including vaults, riser poles, and 138-kV surge arresters for each of the cable terminations. 2. Civil construction costs required to excavate and backfill trenches and pits for the manholes or splice pits. 3. Material and equipment for installing steel casings and PVC conduits at major road crossings. 4. Equipment and labor for pulling the transmission cables. 5. Equipment and personnel for splicing and termination of the transmission cables. 6. Field construction supervision for cable installation and civil construction work. 7. Performing field and laboratory soil thermal resistivity survey. 8. Cost of performing post-construction commissioning tests. 9. As-built plan and profile drawings of the underground lines. 10. Local sales and federal import taxes. 11. Shipping charges for material to the construction site. Table 4-4 contains a summary of the opinion of probable costs. Component Existing Right-of-Way City Streets Material $4,487,000 $3,937,000 Civil Works $9,616,000 $6,077,000 Engineering $603,000 $432,000 Project Management, Inspection $648,000 $648,000 Miscellaneous (Taxes, etc.) $1,053,000 $771,000 Totals $16,424,000 $11,865,000 Table 4-4 - Summary of Underground Transmission Opinion of Probable Costs City of University Park, Texas 4 - 23 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study OPINION OF PROBABLE COSTS FOR GREENVILLE - LOMO ALTO138 KV XLPE UG1 ALTERNATIVE 138 kV XLPE Cable Circuits With 1750 kcmil Segmental Copper Conductor XLPE Cables Date 5/7/06 MVA Rating 239 Route Length (ft) 14,260 Circuits 1 TrenchLength (ft) 14,260 Cables Per Phase 1 Cables Per Trench 3 Manholes/Ckt. 7 Nominal Cable Length (ft) 42,780 3-Ph Terminations 2 Unit Unit Item Description Qnty. Material Material Qnty. Labor Labor Total 1 ROW Prep./Service Roads - 14,260 8 114,080 114,080 2 Trench Excavation, Streets (ft) 1,854 001,854 120 222,456 222,456 3 Trench Excavation, Unpaved (ft) 200 200 50 9,982 9,982 4 Spoil Disposal (cu.yd.) 2,377 10 23,767 23,767 5 Construct Duct Bank (tr.ft.) 14,260 24342,24014,260 32 456,320 798,560 6 Trench Shoring (tr.ft.) 14,260 14,260 30 427,800 427,800 775 Fluidized Thermal Backfill (cu.yd.) 2,377 178,2502,377 10 23,767 202,017 8 Paving Repair (sq.ft.) 3,708 1037,0763,708 8 29,661 66,737 9 Horizontal Directional Drilling (ft) 12,207 38463,84912,207 400 4,882,624 5,346,473 10 Pipe Jacking and Boring (ft) 250 4812,000250 625 156,250 168,250 11 Trench Steel Plating (tr.ft.) 1,854 001,854 10 18,538 18,538 12 Splice Vault (ea.) 7 42,000294,0007 20,000 140,000 434,000 13 138 kV XLPE 1750 kcmil cable (ft.) 43,819 451,971,8641,971,864 14 Ground continuity conductor (ft) 14,260 2.535,6508 2,000 16,000 51,650 15 Duct Mandrel Testing 25 4,000 100,000 100,000 16 Cable Installation (section pulls) 24 8,000 192,000 192,000 17 Ground conductor installation (sections) 8 2,000 16,000 16,000 18 138 kV terminations (ea.) 6 8,00048,0006 8,000 48,000 96,000 19 Manufacturer's field supervisor (week) 12 7,000 84,000 84,000 20 Splice and termination special tools (lot) 1 25,00025,00025,000 21 138 kV, 1-phase splices (ea.) 21 9,000189,00021 9,000 189,000 378,000 55 22 Cross-Bonding Link Boxes 8,14037,9873,000 14,000 51,987 23 3-Ph Grounding Link Boxes 3 6,27020,9003 1,000 3,333 24,233 24 Cable Clamps 245 13031,850245 100 24,500 56,350 25 Upaved ROW restoration (sq.ft.) 399 1399399 1 399 799 26 Cable Termination Structures 2 52,000104,0002 6,000 12,000 116,000 27 Mob./Demobi. Cable Contractor (ea.) 2 30,000 60,000 60,000 28 Mobile Office/Storage Areas 75,000 29 Traffic Control lot 75,000 85,000 30 Security (man-days) 360 300 108,000 108,000 31 Test & Energization (ea) Lump Amt. 20,000 20,000 20,000 32 Emergency repair parts (lot) 1 109,500109,500 0 109,500 33 Subtotal $3,901,565$7,467,477 $11,454,042 34 Specification Preparation $35,000 $35,000 35 Detailed Engineering (ea.) $568,452 $568,452 36 Surveys (lot) $250,000 $250,000 37 Soil Survey $33,000 $33,000 38 Construction Supervision (days) 360 800 $288,000 $288,000 39 Project Management 300 1200 $360,000 $360,000 40 Field Construction Inspection 360 800 $288,000 $288,000 41 Construction Contingency & Profit (20%) $1,493,495 $1,493,495 42 Material Contingency & Profit (15%) $585,235 $585,235 43 Subtotals $4,486,800$10,783,424 7% $1,068,916 44 Sales Tax $16,424,140 Total Cost City of University Park, Texas 4 - 24 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study OPINION OF PROBABLE COSTS FOR GREENVILLE - LOMO ALTO138 KV XLPE UG2 ALTERNATIVE 138 kV XLPE Cable Circuits With 1750 kcmil Copper Conductor XLPE Cables Date 5/7/06 MVA Rating 239 Route Length (ft) 14,260 Circuits 1 TrenchLength (ft) 14,260 Cables Per Phase 1 Cables Per Trench 3 Manholes/Ckt. 7 Nominal Cable Length (ft) 42,780 3-Ph Terminations 2 Unit Unit Item Description Qnty. Material Material Qnty. Labor Labor Total 1 ROW Preparation - 14,260 8 114,080 114,080 2 Trench Excavation, Streets (ft) 12,834 0012,834 120 1,540,080 1,540,080 3 Deep Trench Excavation (ft) 1,426 1,426 312 444,912 444,912 4 Spoil Disposal (cu.yd.) 2,377 12 28,520 28,520 5 Construct Duct Bank (tr.ft.) 14,260 24342,24014,260 32 456,320 798,560 6 Trench Shoring (tr.ft.) 14,260 14,260 30 427,800 427,800 775 Fluidized Thermal Backfill (cu.yd.) 2,377 178,2502,377 10 23,767 202,017 8 Paving Repair (sq.ft.) 30,897 8247,17330,897 3 92,690 339,863 9 Pipe Jacking and Boring (ft) 250 4812,000250 625 156,250 168,250 10 Trench Steel Plating (tr.ft.) 12,834 0012,834 10 128,340 128,340 11 Splice Vault (ea.) 7 42,000294,0007 20,000 140,000 434,000 12 138 kV XLPE 1750 kcmil cable (ft.) 43,819 401,752,7681,752,768 13 Ground continuity conductor (ft) 14,260 2.535,6508 2,000 16,000 51,650 14 Duct Mandrell Tests 25 4,000 100,000 100,000 15 Cable Installation (section pulls) 24 8,000 192,000 192,000 16 Ground conductor installation (sections) 8 2,000 16,000 16,000 17 138 kV terminations (ea.) 6 8,00048,0006 8,000 48,000 96,000 18 Manufacturer's field supervisor (week) 12 7,000 84,000 84,000 19 Splice and termination special tools (lot) 1 25,00025,00025,000 20 138 kV, 1-phase splices (ea.) 21 9,000189,00021 9,000 189,000 378,000 21 Cross-Bonding Link Boxes 5 8,14037,9875 3,000 14,000 51,987 22 3-Ph Grounding Link Boxes 3 6,27020,9003 1,000 3,333 24,233 23 Cable Clamps 245 13031,850245 100 24,500 56,350 24 Upaved ROW restoration (sq.ft.) 2,852 12,8522,852 1 2,852 5,704 25 Cable Termination Structures 2 52,000104,0002 6,000 12,000 116,000 26 Mob./Demobi. Cable Contractor (ea.) 2 30,000 60,000 60,000 27 Mobile Office/Storage Areas 85,000 28 Traffic Control lot 75,000 75,000 29 Security (man-days) 360 300 108,000 108,000 30 Test & Energization (ea) Lump Amt. 20,000 20,000 20,000 31 Emergency repair parts (lot) 1 102,000102,000 0 102,000 32 Subtotal $3,423,670$4,517,444 $8,026,114 33 Specification Preparation $35,000 $35,000 34 Detailed Engineering (ea.) $397,056 $397,056 35 Surveys (lot) $250,000 $250,000 36 Soil Survey $33,000 $33,000 37 Construction Supervision (days) 360 800 $288,000 $288,000 38 Project Management 300 1200 $360,000 $360,000 39 Field Construction Inspection 360 800 $288,000 $288,000 40 Construction Contingency & Profit (20%) $903,489 $903,489 41 Material Contingency & Profit (15%) $513,551$513,551 Subtotals $3,937,221$7,071,989 42 43 7% $770,645 Sales Tax $11,864,854 Total Cost City of University Park, Texas 4 - 25 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study SECTION 5 CONVERSION OF ALLEY AERIAL SERVICES TO UNDERGROUND CONVERSION OF ALLEY ARIEL SERVICES TO UNDERGROUND INTRODUCTION The City of University Park, Texas is considering the feasibility of converting certain overhead utilities (electric distribution, telephone, and cable TV) that serve residential customers from the alleys behind the residences. This could be in conjunction with the City’s “mile-per-year project”, which is an on-going effort to replace existing underground utility lines (gas, water, and sewer) below the alleys throughout the City. This Study is based on the premise that the placement of the aerial services underground will occur concurrently with the reconstruction of the existing underground utilities. This Study takes into consideration the various service provider’s standards and requirements for placing their particular utility services underground. Any additional right-of-way easements required will be addressed. In order to display a proposed layout of the underground services, a typical City block was selected, which is the block bordered in the north and south by Stanford and Amherst Streets and the east and west by Hillside Avenue and Airline Road. Opinions of probable cost are developed for the block area and can be extrapolated for area lengths of more than one block. Two versions of undergrounding these utilities were considered, the first with all utilities placed underground in the alley and the second with the electric, cable, and telephone served from primarily the front of each lot. The latter would not require additional right-of-way in the alley area. EXISTING RIGHT-OF-WAY The City’s alleys have utility rights-of-way of various widths with the majority being either 10-feet or 15- feet wide. The selected block has a 10-foot width. The current underground utilities placed within these rights-of-way are sewer, water, and gas. The existing overhead utilities are supported by wood poles which are also located within the rights-of-way. See Figures 5-1 and 5-2 which show a cross section of the utilities and right-of-way for a 10-foot and 15-foot width, respectively. Figures 5-2 and 5-3 show the cross section of the utilities plus the sanitary sewer service conditions. City of University Park, Texas 5 - 1 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study UTILITY REQUIREMENTS Several meetings and discussions were held with the various entities that would be involved in an alley underground project. The following indicates each utility and some of the salient points of their requirements: 1. Sewer - City of University Park: a. Typically an 8-inch PVC line placed at a depth of 9 to 11 feet below grade. b. Line will be tapped for each residence, sweeping upward toward each residence which requires a minimum of 12-inch clearance to other pipes or objects. 2. Water - City of University Park: a. Typically an 8-inch PVC line placed at a depth of 42 inches below grade. b. Line will be tapped for service lines to each residence’s water meter. 3. Gas - Atmos Energy: a. Typically a 2-inch PVC line placed 2 to 3 feet below grade. b. Line will be tapped with 3/4-inch service line to each residence’s gas meter. 4. Electrical Distribution - TXU Electric Delivery: a. The primary (15-kV), three-phase distribution circuit is to be placed in the street in a 2-by-2, 6-inch conduit, concrete-encased duct bank. Cable size and type is 1,000 kcmil EPR with concentric neutral. b. A four-way or three-way manhole (approximately 12 feet by 12 feet) will be placed in the street every block and will connect the primary duct bank in at least two directions, plus the connection to pad-mounted switchgear. c. The pad-mounted switchgear unit (enclosed in a metal or fiberglass cabinet approximately 6-feet wide by 6-feet long by 5-feet high) placed at each block will connect the primary three-phase circuit to a single-phase (15-kV) circuit that will be fed to a series of pad-mounted transformers. The single circuit line (one 1/0 aluminum, XLPE cable in a 4-inch PVC conduit) will loop through each transformer in the alley and connect to the adjacent block’s switchgear. (See example in Figure 5-5.) City of University Park, Texas 5 - 2 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Figure 5.5 d. Each transformer (assumed to be a 75-kVA unit) will typically serve six residences. See example in Figure 5-6 which includes (left to right) a cable TV pedestal, pad-mounted transformer, and telephone pedestal. The 240/120-volt service drops to each residence will be a three-wire circuit in a PVC conduit. The transformers have been located so each unit can provide service to two residence meters and a circuit to a secondary pedestal which will in turn serve four residences. See Figure 5-7 which shows a cable TV pedestal on the left and an electric secondary pedestal on the right. Figure 5-6 City of University Park, Texas 5 - 3 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Figure 5.7 e. Each pad-mounted transformer will require a footprint area approximately 5-feet deep and 4-feet wide. Working and ventilating clearance to objects is 5 feet with 10 feet required for hot-stick maintenance for the front side. The transformer orientation would need to have this side facing the alley. 5. Telephone - AT&T: a. The telephone system for residences will be sourced from a large 1,200-pair cable or larger which will be connected to a 600-pair cable that will run the length of the alleys. This connection will be made in a handhole (4-feet by 4-feet wide by 8-feet by 4-feet deep) or a traffic bearing manhole (6-feet wide by 8-feet long by 6-feet deep) located near the alley entrance, one per block. b. The 600-pair cable will be installed in a 4-inch conduit the length of the alley in each block. c. A 100-pair cable will also connect in the manhole/handhole and connect to telephone pedestals by looping in and out for the length of the block. Each pedestal will provide service to four residences. 6. Cable TV - Charter Communications: a. The cable TV system for residences will be sourced from a main fiber optic feeder which will be connected to a trunk fiber optic line that runs the length of the alley and connects to two amplifier pedestals per block (approximately 600 feet apart). b. Coaxial cable will then connect to the cable pedestals; each will serve four residences. c. The trunk fiber-optic cable and coaxial cables to the pedestals will be installed in a 4-inch PVC conduit which will have three, 1-1/4-inch subducts contained in the 4- inch conduits. City of University Park, Texas 5 - 4 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study CONSTRUCTION METHODS As described above, almost all of the existing aerial facilities would need to be installed under the alley with the exception of the electrical-distribution, primary, three-phase feeders. Figures 5-1 and 5-2 show the cross section of required right-of-way and clearances for all the utilities. The construction concept is that during the replacement of the existing underground utilities (the pipes), the existing overhead utilities (the wires) would be placed underground utilizing joint-trench participation among the various entities. Figures 5-3 and 5-4 show the cross section of the proposed underground with the existing sanitary sewer service for individual residences. Two of these service connections occur for every lot width (approximately every 50 feet). Likewise, service connections for water and gas will have service connections that rise from the primary line for each residence’s meter (approximately every 50 feet). One of the 4-inch conduits for the telephone lines will continue underground for the length of the block. The other 4-inch conduit would need to rise up to loop into each telephone service pedestal and then return under ground. These telephone conduit risers would be located approximately every 100 feet. The cable TV 4-inch conduit which would contain three subducts would also need to turn up and loop through each amplifier and cable TV service pedestal. These conduit risers would also need to be located approximately every 100 feet. Figure 5-8 shows the electric distribution, cable TV, and telephone services emanating from the alley. As stated earlier, this layout requires additional rights-of-way and easements in the alley and residents' backyards. Figure 5-9 shows an alternative to the alley construction by placing the electric-distribution, pad-mounted transformers and pedestals, and the cable TV and telephone pedestals at the front of the residential lots. This method would alleviate the need for additional rights-of-way in the backyards, but would require additional easements in the front yards and along lot lines between houses to be able to route the service cables to the existing residential connections at the rear of the houses. City of University Park, Texas 5 - 5 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study ADDITIONAL EASEMENTS AND RIGHT-OF-WAY REQUIREMENTS As shown on Figures 5-1 through 5-4, to allow for the placement of the wire utilities underground, additional rights-of-way would be required to allow for these additions to meet the necessary clearance requirements for construction and maintenance. The figures show that a width of 20 feet would be required. Additional rights-of-way will be required along the line route in the alley between Stanford and Amherst for 11 blocks and in the alley between Daniel and University for two blocks. Approximately 92,400 square feet of additional rights-of-way was calculated for the alleys. With the additional rights-of-way available, most of the pad-mounted equipment, including telephone pedestals, cable amplifiers, cable pedestals, and electrical-distribution secondary pedestals, would need to be located in this area outside the paved-alley driving surface. Additional easements may be required for placement of the larger pad-mounted electrical equipment, including the pad-mounted switchgear cabinets and the pad-mounted transformers. The transformers require a much larger area than the service pedestals. As indicated earlier in the Study, the footprint size plus the operating clearance distances, an area of approximately 14-feet wide and 10-feet deep, would be required for each transformer. Additional rights-of-way required for the transformers and pad-mounted switchgear would be approximately 780 square feet. OPINION OF PROBABLE COST An opinion of probable cost was developed for the material and installation of the aerial utilities underground in conjunction with replacing the existing underground sanitary sewer, gas, and water utilities and placing underground in the alley. These costs include only the incremental costs for the electrical, cable, and telephone. These costs were developed based on the single block illustrated on Figure 5-8. The cost per block is approximately $832,000. The cost for the portion of the utilities currently under the Greenville - Loma Alto transmission line is approximately equivalent to 10 blocks, thus a cost of approximately $8,320,000. The cost for purchasing additional rights-of-way for the alley underground construction plus pad-mounted equipment requirements along the line route is approximately $6,036,000, based on a $60-per-square-foot cost. City of University Park, Texas 5 - 6 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Figure 5-9 shows a layout with the service pedestals and transformers located at the front of the lots. The cost per block would be approximately $900,000 due to the longer feeder cable and service drops. The total line route cost would be approximately $9,000,000. This would not require additional rights-of-way in the alley, but would require more in the front of the lots and along lot lines between houses. The approximate cost would be $12,829,200 again based on a $60-per-square-foot cost. City of University Park, Texas 5 - 7 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study Opinion of Probable Cos5/22/200 t6 Front Sheet Job Name:University Park, TX UG Util / Alley Rev. 0Estimator:Andy Haun Start date:01/01/07End date:04/01/07Date:05/22/06 Duration:13WeeksLocation:University Park, TX Bid DateExpires:3-Sep-06 Labor:Bidders: First Shift: Regular rate4,765hrs @$53.85$256,61 8 Overtime rate (diff)0%0 hrs @$18.45$0 Premium rate (diff)5%238 hrs @$36.89$8,780 Subtotal:$265,398 Labor Efficiency$265,398@10.00%$26,540 Subtotal:$291,938 Supervision5.00%$14,597 Subtotal:$306,535 Rate Increase100%$306,535@3.00%$9,1965.6% Per Year Subtotal:$315,731 Total Labor Cost$315,731 Material$216,662 Escalation ($3.00 Copper)$216,662@10.0%$21,666 Subtotal:$238,328 Sales tax6.9%$16,445 Subtotal:$254,773 MBE Participation$0@2.0%$0 Subtotal:$254,773 Total Material Cost$254,773 $1.352 Job Expenses: Tools/Equipment$6,314 Site Superintendent$37,866 Documentation$0 Safety$2,350 Subtotal:$46,530% of L&M Total Job Expense$46,530 8.16% Sub Total Job Cost$617,034 Contractor Overhead & Profit15.0%$92,555 Engineering10.0%$61,703 Estimating Contingency10.0%$61,703 Subcontractors$0 $0 Subtotal:$0 Total SubcontractorsMarkup10.0%$0 BondingSubtotal:$00.72%$0 TOTAL:$832,995 Distribution Rates: Labor:4765 hrs @$113.339Distr rate$540,068 Material:$216,662@$1.352Distr rate$292,927 Expenses$46,530@$1.150Distr rate$53,510 Subcontractors:$0@$1.100Distr rate$0 TOTAL: $832,995 Base:$832,995 Difference:$0 File: UnivParkUGUtilAlley0506 / Front Sheet 5/22/2006 3:36 PM Opinion of Probable Cos t Basic Field Cost s University Park, TX UG Util / Alley Rev. 5/22/200 Job Name:06 University Park, T Location:X Projected StartEnd 01/01/0704/01/0790Cal. days 64Wk. days 13Weeks RATES: Average manpower :4,765hrs +10%5,242hrs (incl lost time) Single shift:8 hrs per day10men 1-Shift 10 Hr10 hrs per day10men Double shift:20 hrs per day4men Present wage rates:Expire: 3-Sep-06JWFMGF FIRST SHIFT: Straight time:$53.854$57.789$59.764 LU#124 - MOOvertime:$72.300$78.035$80.911 Kansas City, MOPremium:$90.745$98.282$102.058 SECOND SHIFT: Journeyman:$0.000$0.000$0.000 Differential to ST:($53.854)($53.854)($53.854) Supt. Rate: Regular rate:40hrs @$59.764$2,390.56 LU#124 - M OOvertime rate:5hrs @$80.911$404.56 Kansas City, MOPremium rate:0hrs @$102.058$0.00 KC GF Rate Weekly Subtotal:$2,795.12 Second shift:0%@7.47%$0.00 Weekly Subtotal:$2,795.12 Average cost:45hrs work week:$62.11(per hour) JOB EXPENSES:% of Labor & Material: 8.16 % Administrative Costs : Supt living:0wks @$450$0 Supt wages:13wks @$2,795$35,937 Supt truck:13wks @$150$1,929 Added supt:0wks @$2,795$0 Added truck:0wks @$150$0 Office trailer:0mo @$500$0 Office utilities:0mo @$200$0 PM travel:0trips$300$0$37,866 Documentation :Engineering:0hrs @$65$0 Drafting:0hrs @$45$0$0 Safety Costs: Safety equip:10men@$135$1,350 Drug Testing10men@$50$500(1.5 hrs) Safety Meeting10hrs @$50$500$2,350 Miscellaneous : Expendables1.0%labor$315,731$3,157 Small tools1.0%labor$315,731$3,157 Lift delivery0@$125.00$0 65' Genie0mo@$2,050.00$0 45' Genie0mo@$1,200.00$0$6,314 TOTAL EXPENSES:$46,530 File: UnivParkUGUtilAlley0506 / Expenses 5/22/2006 3:37 PM Opinion of Probable Cost 05/22/06 Distribution Sheet Job:University Park, TX UG Util / Alley Rev. 0Labor$113.339 City:University Park, TXMaterial$1.352 Subs$1.100 PROPOSAL BREAKDOWN: ItemDescriptionLaborMaterial HrsSellCostSellTOTAL 115kV Power921$104,372$130,194$176,022$280,394 2120/240V Power1,266$143,435$31,587$42,706$186,141 3Telephone1,491$169,007$27,671$37,411$206,418 4Cable TV847$96,053$25,210$34,085$130,138 5Electrical Power and Comm System Startup240$27,201$2,000$2,704$29,905 6Gas0$0$0$0$0 7Water0$0$0$0$0 8Sanitary Sewer0$0$0$0$0 9Pavement Removal and Replacement0$0$0$0$0 1000$0$0$0$0 1100$0$0$0$0 1200$0$0$0$0 1300$0$0$0$0 1400$0$0$0$0 1500$0$0$0$0 1600$0$0$0$0 Grand Totals4,765$540,068$216,662$292,928$832,996 Front sheet totals:4,765$540,068$216,662$292,927$832,995 Difference:0$0$0($1)($1) File: UnivParkUGUtilAlley0506 / Distribution 5/22/2006 3:37 PM Sega, Inc. 05/22/06 Opinion of Probable Cost Takeoff Sheets University Park, TX UG Util / Alley Rev. 0 1Sheet:15kV Power LaborLaborMaterialMaterial QuantityDescriptionPerPer UnitExtensionUnitExtension Ductbank at Lot Front 1,200Excav/Bkfil Unit Labor & Equip at 50' per hour2.00c24.00$75.00c$900.00 2,4006"PVC6.75c162.00$194.00c$4,656.00 120 - 6" PVC Coupling0.35e42.00$8.00e$960.00 240 - 6" PVC Chairs0.18e43.20$1.40e$336.00 4 - 6" Elbows GRS3.75e15.00$250.00e$1,000.00 1,200Concrete per ft 2'x2' Ductbank at $75 per CYe$11.11e$13,332.00 1Prefabricated Manhole16.00e16.00$5,000.00e$5,000.00 Extend Ductbank to Padmt Sw 120Excav/Bkfil Unit Labor & Equip at 50' per hour2.00c2.40$75.00c$90.00 1206"PVC6.75c8.10$194.00c$232.80 6 - 6" PVC Coupling0.35e2.10$8.00e$48.00 12 - 6" PVC Chairs0.18e2.16$1.40e$16.80 4 - 6" Elbows GRS3.75e15.00$250.00e$1,000.00 120Concrete per ft 2'x2' Ductbank at $75 per CYe$11.11e$1,333.20 1S&C PMH-Series 15kV Padmt Switch Complete32.00e32.00$16,000.00e$16,000.00 Ductbank for Alley Distribution 80Excav/Bkfil Unit Labor & Equip at 50' per hour2.00c1.60$75.00c$60.00 1204" PVC4.50c5.40$159.59c$191.51 6 - 4" PVC Couplings0.19e1.14$5.00e$30.00 12 - 4" PVC Chairs0.13e1.56$1.00e$12.00 4 - 4" Field Bends1.20e4.80$5.00e$20.00 1,280Concrete per ft 1'x1' Ductbank at $75 per CYe$5.56e$7,116.80 Feeder Cable & Terminations 4,09215kV 1000MCM Al URD EPR/CPE 1/3N80.00m327.36$13,900.00m$56,878.80 1,50015kV 1/0AWG Al URD EPR/CPE 1N25.00m37.50$3,900.00m$5,850.00 8 #1000 15KV Termination Stress Cone6.00e48.00$100.00e$800.00 2 #1/0 15KV Termination Stress Cone2.50e5.00$85.00e$170.00 Transformers including C. Riser & 15kV Term 875kVA 15kV:120/240 6.00e48.00$1,500.00e$12,000.00 8 - 10' x3/4'' Ground Rod1.50e12.00$18.00e$144.00 484" PVC4.50c2.16$159.59c$76.60 16 - 4" Field Bends1.20e19.20$5.00e$80.00 12815kV 1/0AWG Al URD EPR/CPE 1N25.00m3.20$3,900.00m$499.20 16 #1/0 15KV Termination Stress Cone2.50e40.00$85.00e$1,360.00 Note: Excludes Concrete/Ashpalt Cut/Patch TOTALS: 920.88$130,194 Project: UnivParkUGUtilAlley0506 / Takeoff 5/22/2006 3:37 PM Page 1 of 6 2Sheet:120/240V Power LaborLaborMaterialMaterial QuantityDescriptionPerPer UnitExtensionUnitExtension 120/240 Extensions to Pedestals (8 avg. 60') 8120/240V Distribution Pedestal8.00e64.00$75.00e$600.00 4804" PVC4.50c21.60$159.59c$766.03 16 - 4" Field Bends1.20e19.20$5.00e$80.00 1,920500MCM XHHW44.00m84.48$3,443.29m$6,611.12 48500MCM termination0.70e33.60$22.39e$1,074.72 640#4 XHHW14.00m8.96$381.57m$244.20 16#4 termination0.35e5.60$3.00e$48.00 (Share Alley Excav/Bkfil w/ 15kV Ductbank) Service Drops (46 avg. 60') 2,7601 1/2 " PVC2.75c75.90$50.09c$1,382.48 184 - 1 1/2" Field Bends1.15e211.60$5.00e$920.00 46 - 1 1/2" Male Adaptors0.20e9.20$2.50e$115.00 3681 1/2" GRC12.00c44.16$344.13c$1,266.40 46 - 1 1/2" Myers hubs0.50e23.00$3.45e$158.70 92 - 1 1/2" Conduit supports0.18e16.56$4.30e$395.60 11,040#3/0 XHHW26.00m287.04$1,188.71m$13,123.36 276#3/0 termination0.90e248.40$8.17e$2,254.92 3,680#6 XHHW13.00m47.84$249.01m$916.36 92#6 termination0.30e27.60$2.72e$250.24 1,840Excav/Bkfil Unit Labor & Equip at 50' per hour2.00c36.80$75.00c$1,380.00 (Use Backhoe to Share Excav/Bkfil w/ T & C) Note: Excludes Concrete/Ashpalt Cut/Patch TOTALS: 1265.54$31,587 Project: UnivParkUGUtilAlley0506 / Takeoff 5/22/2006 3:37 PM Page 2 of 6 3Sheet:Telephone LaborLaborMaterialMaterial QuantityDescriptionPerPer UnitExtensionUnitExtension Trunk Line in Alley 2Prefabricated Pavement-rated HandHole8.00e16.00$2,000.00e$4,000.00 12Telephone Distribution Pedestal4.00e48.00$150.00e$1,800.00 2,6004" PVC4.50c117.00$159.59c$4,149.34 16 - 4" Field Bends1.20e19.20$5.00e$80.00 28 - 4" Male Adaptors0.35e9.80$4.00e$112.00 1,300Telephone 600 pr Cable40.00m52.00$6,000.00m$7,800.00 1,300Telephone 100 pr Cable25.00m32.50$3,000.00m$3,900.00 3001PR #20 Termination (one end )2.50e750.00$0.75e$225.00 Service Drops (46 avg. 60') 2,7601" PVC2.00c55.20$29.57c$816.13 184 - 1" Field Bends1.00e184.00$5.00e$920.00 46 - 1" Male Adaptors0.15e6.90$2.00e$92.00 3681" GRC8.00c29.44$203.21c$747.81 46 - 1" Myers hubs0.40e18.40$2.54e$116.84 92 - 1" Conduit supports0.12e11.04$2.25e$207.00 2,760Tray Cable FREP/CPE #16 Shld 4PR18.00m49.68$880.00m$2,428.80 924PR #16 Termination (one end )1.00e92.00$3.00e$276.00 Note: Excav/Bkfil incl with Elec Power TOTALS: 1491.16$27,671 Project: UnivParkUGUtilAlley0506 / Takeoff 5/22/2006 3:37 PM Page 3 of 6 4Sheet:Cable TV LaborLaborMaterialMaterial QuantityDescriptionPerPer UnitExtensionUnitExtension Trunk Line in Alley 2Prefabricated Pavement-rated HandHole8.00e16.00$2,000.00e$4,000.00 10Cable Distribution Pedestal4.00e40.00$150.00e$1,500.00 2Cable Distribution Pedestal / Amplifier6.00e12.00$2,500.00e$5,000.00 1,3004" PVC4.50c58.50$159.59c$2,074.67 8 - 4" Field Bends1.20e9.60$5.00e$40.00 14 - 4" Male Adaptors0.35e4.90$4.00e$56.00 1,300Thick-net Coax Cable25.00m32.50$4,000.00m$5,200.00 28Coaxial Cable 59/U Terminations2.50e70.00$2.50e$70.00 Service Drops (46 avg. 60') 2,7601" PVC2.00c55.20$29.57c$816.13 184 - 1" Field Bends1.00e184.00$5.00e$920.00 46 - 1" Male Adaptors0.15e6.90$2.00e$92.00 3681" GRC8.00c29.44$203.21c$747.81 46 - 1" Myers hubs0.40e18.40$2.54e$116.84 92 - 1" Conduit supports0.12e11.04$2.25e$207.00 2,760Thin-net Coax Cable25.00m69.00$1,500.00m$4,140.00 92Coaxial Cable 59/U Terminations2.50e230.00$2.50e$230.00 Note: Excav/Bkfil incl with Elec Power TOTALS: 847.48$25,210 5Sheet:Electrical Power and Comm System Startup LaborLaborMaterialMaterial QuantityDescriptionPerPer UnitExtensionUnitExtension 1Power and Signal System Testing160.00e160.00$2,000.00e$2,000.00 1Coordinate Outages and Changeovers80.00e80.00e TOTALS: 240.00$2,000 Project: UnivParkUGUtilAlley0506 / Takeoff 5/22/2006 3:37 PM Page 4 of 6 6Sheet:Gas LaborLaborMaterialMaterial QuantityDescriptionPerPer UnitExtensionUnitExtension Distribution Line 1,300Excav Unit Labor & Equip at 50' per hour2.00c26.00$75.00c$975.00 1,300Backfill Unit Labor & Equip at 100' per hour1.00c13.00$200.00c$2,600.00 2Connection to Existing Gas Distributione$2,000.00e$4,000.00 1,300Gas Distribution Line, 2" PEe$3.37e$4,381.00 Service Drops (46 avg. 60') 46Tee Connectione$70.00e$3,220.00 46Service Valvee$165.00e$7,590.00 2,760Gas Distribution Line, 1/2" PEe$2.29e$6,320.40 46Connection to Existing Metere$70.00e$3,220.00 Note: Unit Costs from Means Bldg Cost Data TOTALS: 7Sheet:Water LaborLaborMaterialMaterial QuantityDescriptionPerPer UnitExtensionUnitExtension Distribution Line 2Connection to Existing Water Distributione$1,000.00e$2,000.00 1Valve & Connection Lump Sume$230.00e$230.00 1,300Water Distribution Line, 8" PVCe$17.58e$22,854.00 Service Drops (46 avg. 60') 46Tee Connectione$195.00e$8,970.00 2,760Water Distribution Line, 1" PVCe$1.49e$4,112.40 46Connection to Existing Metere$195.00e$8,970.00 Note: Excav/Bkfil incl with Gas Distribution Note: Unit Costs from Means Bldg Cost Data TOTALS: Project: UnivParkUGUtilAlley0506 / Takeoff 5/22/2006 3:37 PM Page 5 of 6 8Sheet:Sanitary Sewer LaborLaborMaterialMaterial QuantityDescriptionPerPer UnitExtensionUnitExtension Distribution Line 2Connection to Existing Linee$1,000.00e$2,000.00 1,300Sanitary Sewer Line, 8" PVCe$7.94e$10,322.00 Service Drops (46 avg. 60') 46Connection to Linee$620.00e$28,520.00 Note: Excav/Bkfil incl with Gas Distribution Note: Unit Costs from Means Bldg Cost Data TOTALS: 9Sheet:Pavement Removal and Replacement LaborLaborMaterialMaterial QuantityDescriptionPerPer UnitExtensionUnitExtension 1Lump Sum Estimate for Alleye$50,000.00e$50,000.00 1Lump Sum for Misc. Sidewalks & Drivese$20,000.00e$20,000.00 TOTALS: Project: UnivParkUGUtilAlley0506 / Takeoff 5/22/2006 3:37 PM Page 6 of 6 Sega, Inc. Opinion of Probable Cost Distribution Job:University Park, TX UG Util / Alley Rev. 0 City:University Park, TX Cost Breakdown: ItemDescriptionLaborMaterialTotal 115kV Power$104,372$176,022$280,394 2120/240V Power$143,435$42,706$186,141 3Telephone$169,007$37,411$206,418 4Cable TV$96,053$34,085$130,138 5Electrical Power and Comm System Startup$27,201$2,704$29,905 6Gas$0$0$0 7Water$0$0$0 8Sanitary Sewer$0$0$0 9Pavement Removal and Replacement$0$0$0 100$0$0$0 110$0$0$0 120$0$0$0 130$0$0$0 140$0$0$0 150$0$0$0 Grand Totals$540,068$292,928$832,996 Note: Breakdowns include 15% O&P, 10% Engineering, and 10% Contingency File: UnivParkUGUtilAlley0506 / Distribution 5/22/2006 3:37 PM SECTION 6 CONCLUSIONS CONCLUSIONS Sections 3, 4, and 5 consider the various transmission and utility alternatives independently. The following table summarizes various combinations of alternatives ranging from rebuilding the existing line to the existing design parameters to placing transmission, distribution, and telecommunications utilities underground. City of University Park, Texas 6 - 1 Sega Project No. 06-0069 138-kV Underground Transmission Feasibility Study